The invention relates to an arrangement for supporting a crankshaft of a multicylinder internal-combustion engine having side walls forming a crankcase and connected firmly to a cylinder block and having bearing shells which are connected to said cylinder block and provided with fitted bearing caps to receive the crankshaft.
A multi-cylinder internal-combustion engine is described in German Published Unexamined Pat. App. (DE-OS) No. 3,544,215. The cylinder block of this engine comprises a section which defines the cylinder and a section connected firmly to the latter, or produced integrally with it, which forms the side walls of a crankcase. Bearing walls are fitted between the individual cylinders, connected to the cylinder block and extend from one of the side walls to the other side wall, the bearing walls being provided at their lower surface with semicircular recesses which serve as bearing blocks for a crankshaft.
It is a disadvantage of such an arrangement that the transverse vibrations of the crank transmission, which cause noise, are transmitted through the bearings and the bearing walls to the flexurally soft side walls of the cylinder block and intensive noise emission therefore originates from the side walls of the cylinder block.
An object of the invention is to develop an arrangement of the above-noted type for supporting a crankshaft so that the transverse vibrations of the crank transmission are kept away from the cylinder block and its side walls and no noise is transmitted to said side walls.
This object is achieved according to the invention by providing an arrangement wherein the support elements connected to the cylinder block are formed geometrically as columnar support elements which support the bearing shell at their lower end and exhibit no direct connection to the side walls of the crankcase, and wherein the fitted bearing caps are mutually connected through a continuous bearing bridge which extends in the longitudinal direction of the internal-combustion engine. Further developments and advantages of the invention are discussed below.
In especially preferred embodiments, column elements which carry bearing shells at their lower end are attached to a cylinder block of a multicylinder internal-combustion engine. A crankshaft is inserted into said bearing shells and secured by bearing caps which are screwed to the bearing shells. The bearing caps are mutually connected by a continuous bearing bridge which extends in the longitudinal direction of the internal-combustion engine.
Forces introduced from the crankshaft into the bearings are absorbed in the vertical direction through the column elements of the cylinder block.
Transverse forces are divided approximately as to one half, through the column elements to the cylinder block on the one hand, and to the bridge strut of the bearing bridge which connects the bearing caps on the other hand.
In this way the cylinder block is relieved of transverse flexure and the generation of noise is therefore reduced. Because the bearings exhibit no direct connection with the side walls of the crankcase, there is also no direct transmission of noise to these noise-emitting parts. Moreover, the transverse resilience of the column elements causes a further displacement of the transverse forces from the cylinder block to the bridge strut of the bearing bridge.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.